The first material used for lasers was synthetic ruby crystals. Ruby lasers are still used for a few applications, but they are not common because of their low power efficiencies. At room temperature, ruby lasers emit only short pulses of light, but at cryogenic temperatures they can be made to emit a continuous train of pulses.[4]

Mode locking of solid-state lasers and fiber lasers has wide applications, as large-energy ultra-short pulses can be obtained. There are two types of saturable absorbers that are widely used as mode lockers: SESAM,[6][7][8] and SWCNT. Graphene has also been used.[9][10][11] These materials use a nonlinear optical behavior called saturable absorption to make a laser create short pulses.

The U.S. Army is preparing to test a truck-mounted laser system using a 58 kW fiber laser.[20] The scalability of the laser opens up use on everything from drones to massive ships at different levels of power. The new laser puts 40 percent of available energy into its beam, which is considered very high for solid-state lasers. Since more and more military vehicles and trucks are using advanced hybrid engine and propulsion systems that produce electricity for applications like lasers the applications are likely to proliferate in trucks, drones, ships, helicopters and planes.[20]